Method test_two_fields_one_default

Lib/test/test_dataclasses/__init__.py:133–175

(self)

        self.assertEqual(o.x, 32)

    def test_two_fields_one_default(self):
        @dataclass
        class C:
            x: int
            y: int = 0

        o = C(3)
        self.assertEqual((o.x, o.y), (3, 0))

        # Non-defaults following defaults.
        with self.assertRaisesRegex(TypeError,
                                    "non-default argument 'y' follows "
                                    "default argument 'x'"):
            @dataclass
            class C:
                x: int = 0
                y: int

        # A derived class adds a non-default field after a default one.
        with self.assertRaisesRegex(TypeError,
                                    "non-default argument 'y' follows "
                                    "default argument 'x'"):
            @dataclass
            class B:
                x: int = 0

            @dataclass
            class C(B):
                y: int

        # Override a base class field and add a default to
        #  a field which didn't use to have a default.
        with self.assertRaisesRegex(TypeError,
                                    "non-default argument 'y' follows "
                                    "default argument 'x'"):
            @dataclass
            class B:
                x: int
                y: int

            @dataclass
            class C(B):
                x: int = 0

    def test_overwrite_hash(self):
        # Test that declaring this class isn't an error.  It should